I actually found one in the daily mini-vision, at Shrine of the Seven Stars. This zone at least wasn't covered, and there might be more.

I had a quick look today. Seems 1570 is the map ID that corresponds with the mini vision where you looted a Skyshard.

https://wow.tools/maps/worldmap.php?id=1570&bc=b8a03ea551a7bbcee507b1838064792c

I didn't find any others. 1530 (BFA Vale) uses the same map ID, regardless of where the corruption is.

Neat! I was mostly thinking about stuff like Guo-Lai Halls, but I just checked and it doesn't seem to have a separate mapID.

The only thing I'd want to check before resolving this: Does the Horde version of the Vision use a different map? 1570 clearly is the Alliance version.

I can't really look into this as it's currently the Uldum week, but soon (tomorrow) this will change so I suppose I shouldn't forget :)

For what it's worth, I added the missing zone in 6c73c7c.

Just checked the lesser vision on my horde character. It is the same place.

Thanks! Time to close this issue, then.